Effects of oxytetracycline-HCl on reproductive performance of turkey breeder hens from the 13 to 24-wk production period were evaluated. During the 13th wk of production, females were grouped into low, medium, and high fertility subclasses. Females within each fertility subclass were randomly reassigned to treatments. The antibiotic was administered via the drinking water (T-2) or via the drinking water plus an intravaginal lavage (T-3). Hens receiving T-2 treatment showed significantly higher fertility than untreated controls (T-1) but also showed significantly higher early embryonic mortality than those receiving the T-3 treatment. Hatchability of all egg set was significantly higher in both antibiotic-treated groups than in controls. Females in the fertility subclasses remained significantly different from each other throughout the experiment. To determine the duration of the effect of antibiotic treatment, eggs were collected in a treatment and posttreatment periods. Fertility (P less than .05), and hatchability (P less than .10) were improved during the treatment period compared with results of the posttreatment period. The T-3 treatment had a long-term effect: it maintained early embryonic mortality at 10% and hatchability at the same level during both treatment periods. A short-term effect was observed in the T-2 group; early embryonic mortality increased (P less than .05) and hatchability decreased (P less than .10) during the posttreatment period. No correlations were found between mycoplasmal or bacterial populations and fertility subclass or antibiotic treatment. Egg production, body weight, feed consumption, feed consumed per egg, egg weight, and egg specific gravity were unaffected by antibiotic treatment.